No difference in morphokinetics between male and female preimplantation embryos from ART

Research question: Do morphokinetic parameters vary between male and female preimplantation embryos?Design: This was a retrospective cohort study of 175 cycles between March 2018 and June 2021 at two reproductive centres. It included time-lapse data from 92 female and 83 male preimplantation embryos exclusively issued from fresh oocyte donation and undergoing intracytoplasmic sperm injection (ICSI). Only fresh elective single-embryo transfers on day 5 were assessed, and the sex of the embryo was confirmed at birth. The morphokinetic parameters analysed were measured in hours post -insemination (hpi). A two-tailed Student's t-test was used to compare the morphokinetics between embryo sexes and a value of P < 0.05 was considered statistically significant.Results: Following strict inclusion criteria to avoid poor-quality preimplantation embryos, no significant differences were found in morphokinetic parameters when comparing cycles that resulted in female versus male live births for the following: time to pronuclear fading (22.1 & PLUSMN; 2.4 versus 22.4 & PLUSMN; 2.9 hpi; P = 0.52); time to the 2-cell stage (24.6 & PLUSMN; 2.5 versus 25.0 & PLUSMN; 2.5 hpi; P = 0.34); time to the 3-cell stage (35.3 & PLUSMN; 3.3 versus 35.8 & PLUSMN; 3.1 hpi; P = 0.28); time to the 4-cell stage (36.3 & PLUSMN; 3.4 versus 36.9 & PLUSMN; 3.7 hpi; P = 0.20); time to the 5-cell stage (47.9 & PLUSMN; 4.6 versus 48.0 & PLUSMN; 4.8 hpi; P = 0.88); time to the 8-cell stage (54.0 & PLUSMN; 6.5 versus 54.1 & PLUSMN; 6.5 hpi; P = 0.91); time to the start of blastulation (86.3 & PLUSMN; 14.6 versus 85.7 & PLUSMN; 15.5 hpi; P = 0.78); and time to the full blastocyst stage (93.0 & PLUSMN; 16.9 versus 93.2 & PLUSMN; 17.2 hpi; P = 0.94).Conclusions: There are no significant differences in morphokinetics between male and female preimplantation embryos.

Automated summary

This study found no significant differences in morphokinetic parameters between male and female preimplantation embryos.